/**
 * Copyright (c) 2010, Daniel Bimschas and Dennis Pfisterer, Institute of Telematics, University of Luebeck
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 *
 * 	- Redistributions of source code must retain the above copyright notice, this list of conditions and the following
 * 	  disclaimer.
 * 	- Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 * 	  following disclaimer in the documentation and/or other materials provided with the distribution.
 * 	- Neither the name of the University of Luebeck nor the names of its contributors may be used to endorse or promote
 * 	  products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package de.uniluebeck.itm.nettyprotocols.isense.ishellinterpreter;

import de.uniluebeck.itm.nettyprotocols.isense.ISensePacket;
import de.uniluebeck.itm.nettyprotocols.isense.ISensePacketType;
import de.uniluebeck.itm.nettyprotocols.util.HandlerTools;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.slf4j.LoggerFactory;

public class IShellInterpreterHandler extends SimpleChannelHandler {

	private final org.slf4j.Logger log;

	private ChannelHandlerContext context;

	public IShellInterpreterHandler() {
		this(null);
	}

	public IShellInterpreterHandler(String instanceName) {
		log = LoggerFactory.getLogger(instanceName != null ? instanceName : IShellInterpreterHandler.class.getName());
	}

	@Override
	public void channelDisconnected(final ChannelHandlerContext ctx, final ChannelStateEvent e) throws Exception {
		context = null;
		super.channelDisconnected(ctx, e);
	}

	@Override
	public void channelConnected(final ChannelHandlerContext ctx, final ChannelStateEvent e) throws Exception {
		log.debug("----IShellInterpreterHandler:connected----");
		if (ctx == null) {
			log.debug("received null ctx channel");
		}
		context = ctx;
		super.channelConnected(ctx, e);

//        setChannel((byte) 11);
	}

	@Override
	public void writeRequested(ChannelHandlerContext ctx, MessageEvent e) throws Exception {

		if (e.getMessage() instanceof IShellInterpreterSetChannelMessage) {
			IShellInterpreterSetChannelMessage msg = (IShellInterpreterSetChannelMessage) e.getMessage();
			setChannel(msg.getChannel());
		} else if (e.getMessage() instanceof ChannelBuffer) {
			log.debug("setting channel");
			ChannelBuffer cbuf = (ChannelBuffer) e.getMessage();
			if ((cbuf.getByte(0) == ISensePacketType.CODE.getValue()) &&
					(cbuf.getByte(1) == IShellInterpreterPacketTypes.COMMAND_SET_CHANNEL.getValue())) {
				setChannel(cbuf.getByte(2));
			} else {
				super.writeRequested(ctx, e);
			}

		} else {
			super.writeRequested(ctx, e);
		}

	}

	public void setChannel(byte channelNumber) {
		if (this.context == null) {
			throw new RuntimeException("Channel not yet connected");
		}

		ChannelBuffer buffer = ChannelBuffers.buffer(3);
		buffer.writeByte(ISensePacketType.CODE.getValue());
		buffer.writeByte(IShellInterpreterPacketTypes.COMMAND_SET_CHANNEL.getValue());
		buffer.writeByte(channelNumber);

		log.debug("Setting channel to {}", channelNumber);
		HandlerTools.sendDownstream(new ISensePacket(buffer), context);
	}

}
